National Weather ServiceCaliforniaExtreme Heat WarningArchive to October 1, 2026
Extreme Heat Warnings in California
The National Weather Service issued 25 extreme heat warnings for California in 2025 and 28 a year on average in 2008-2025; in 2021-2025 it had the 3rd most of any state. 2026 through September: 35, 26% above the average of 28 for those months in 2008-2025. Imperial Valley was covered most often (76 times since 2008).
How many extreme heat warnings does California get?
Every extreme heat warning that covered part of California. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 35 |
| 2025 | 25 |
| 2024 | 49 |
| 2023 | 30 |
| 2022 | 35 |
| 2021 | 61 |
| 2020 | 51 |
| 2019 | 32 |
| 2018 | 35 |
| 2017 | 35 |
| 2016 | 21 |
| 2015 | 12 |
| 2014 | 7 |
| 2013 | 11 |
| 2012 | 23 |
| 2011 | 13 |
| 2010 | 12 |
| 2009 | 16 |
| 2008 | 40 |
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
When in the year does California get them?
Sum of 2008-2025; the busiest month is labelled.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
Where in California?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Imperial Valley | 76 | 30 | September 8, 2026 |
| Imperial County West | 76 | 30 | September 8, 2026 |
| San Bernardino County-Upper Colorado River Valley | 74 | 20 | September 10, 2026 |
| Imperial County | 73 | 0 | August 17, 2016 |
| Including the Mojave National Preserve | 72 | 16 | August 24, 2026 |
| Chuckwalla Valley | 72 | 29 | September 8, 2026 |
| San Diego County Deserts | 71 | 28 | September 8, 2026 |
| Morongo Basin | 71 | 14 | August 24, 2026 |
| Lower Colorado River Valley CA | 70 | 0 | July 27, 2016 |
| Death Valley National Park | 70 | 18 | September 10, 2026 |
| Coachella Valley | 70 | 27 | September 8, 2026 |
| Riverside County/Eastern Deserts | 69 | 0 | July 27, 2016 |
The NWS issues these products for counties or forecast zones; a zone can be part of a county or a mountain range.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
The latest extreme heat warnings for California in AreaZine's record
NWS San DiegoWarningOctober 1, 2026
Extreme Heat Warning: Orange County Coastal, CA
In force until 8:00 p.m. PDT, October 8, 2026
NWS Las VegasWarningSeptember 9, 2026
Extreme Heat Warning: Lake Havasu and Fort Mohave, Lake Mead - AZ side, Lake Mohave - AZ side and 9 more, AZ and CA
Expired 8:00 p.m. PDT, September 10, 2026
NWS San DiegoWarningSeptember 9, 2026
Extreme Heat Warning: San Diego County Coastal Areas and Orange County Coastal, CA
Expired 8:00 p.m. PDT, September 9, 2026
NWS Los Angeles/OxnardWarningSeptember 8, 2026
Extreme Heat Warning: Malibu Coast, Los Angeles County Beaches, Palos Verdes Hills and 7 more, CA
Expired 8:00 p.m. PDT, September 10, 2026
NWS PhoenixWarningSeptember 7, 2026
Extreme Heat Warning: Imperial County Southwest, CA
Expired 8:00 p.m. PDT, September 11, 2026
NWS PhoenixWarningAugust 24, 2026
Extreme Heat Warning: Joshua Tree NP East, Salton Sea, Chuckwalla Mountains and 1 more, CA
Expired 8:00 p.m. PDT, August 28, 2026
NWS Los Angeles/OxnardWarningAugust 24, 2026
Extreme Heat Warning: Cuyama Valley, CA
Expired 8:00 p.m. PDT, August 28, 2026
NWS San DiegoWarningAugust 24, 2026
Extreme Heat Warning: Apple and Lucerne Valleys, CA
Expired 8:00 p.m. PDT, August 28, 2026
This list is AreaZine's record of the NWS alert feed, kept since April 6, 2026; the counts above come from the complete IEM archive.
Source: National Weather Service alerts (api.weather.gov).
What is an extreme heat warning?
An extreme heat warning means dangerous heat is expected, measured by heat index or temperature thresholds each office sets. It replaced the excessive heat warning in 2025. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. AreaZine's counts include the excessive heat warnings issued before the change. The national record · Every warning type in California.